1. Field of the Invention
The invention pertains to earth working equipment, more particularly to a machine comprising a soil disrupter for slicing through the soil and an apparatus for inserting silt fence into the soil in a secure and proper position.
2. Description of Prior Act
In the construction field, silt fence is a synthetic material, about the weight of canvas and 91 cm to 107 cm wide, installed around construction sites, disturbed areas, and in ditches to retain silt while allowing water to slowly pass through. Approximately, 46 cm to 56 cm remains above the ground supported by posts, and the balance is buried in the ground as an anchor. Most installation procedures follow engineering specifications calling for a trench 300 mm deep and 150 mm wide with a lap of silt fence covering the bottom of the trench to be covered and compacted with soil.
Erosion control, including silt fence, is mandated on all federal projects and on many urban projects, both public and private. Millions of feet are installed each year. An improvement in the speed of installation would reduce costs to the public that are both taxpayers and consumers. An improvement in the speed of installation would reduce costs to the public who are both taxpayers and consumers. An improvement in quality would reduce erosion into our environment.
There are a few mowboard plow type machines within the industry, which have been adapted to open up a trench, lay fabric down, and pull soil back over the fabric to hold it in place. These machines are large, bulky, and move a lot of soil, which is difficult to backfill in most situations. They do not conform to engineering specifications because of the large trench they form and poor compaction capabilities. Also, the large machines are difficult to maneuver in many areas required for silt fence.
Contractors from all over the country, hands-on people and large companies knowledgeable in the art and part of the industry, have attempted to build a machine that installs silt fence efficiently and effectively. None have designed a means to do so, and no one utilizes any of the existing patents or any part thereof, to any commercial, or private success.
Currently, most contractors use a trenching machine to dig and excavate a 150 mm deep trench, after which they pound in steel posts, manually hang silt fence on the posts with a short lip of fabric on the bottom of the trench for soil to rest on, and then manually backfill by pushing the excavated soil into the open trench with a blade on their machine.
1. U.S. Pat. No. 5,320,454 to Walling, which illustrates a roller machine for installing a flexible panel. This machine bends a semi-rigid panel, via a system of rollers, 180 and directs it vertically into a previously dug trench.
2. U.S. Pat. No. 4,929,126 to Steenbergen et al., which illustrates a method for installing a screen in the soil. This system defines a screen, which is modified at the manufacturing point so that it does not drop or sag in the still open, previously dug trench, before it is backfilled, or the screen is actually filled to take up the void of the trench.
3. U.S. Pat. No. 4,927,297 to Simpson, which illustrates a leak prevention structure, method apparatus. This system builds a wall under ground level by driving a beam into the ground in a sequence of successive insertions, and then drops a curtain wall into the compacted trench.
4) U.S. Pat. No. 4,720,212 to Steenbergen, et al, which illustrates excavating a trench and inserting a fabric material with a series of rods, rollers, and plates which attempt to unfold or unravel fabric which has been folded and placed on a roll. This system is very cumbersome and is unlikely that the fabric unfolds in a reasonable manner because there is no way to maintain even tension on the fabric while it is pulling off of the roll. Any uneven tension would cause bunching and failure to operate.
5) U.S. Pat. No. 4,705,427 to Atkins illustrates installing fabric into the soil in an elongated furrow path. While different from the current proposal, it was identified by U.S. Pat. No. 2,393,395 to Millard.
6) U.S. Pat. No. 4,200,410 to Baker et al., which illustrates a cable laying device. This machine excavates a trench in frozen or unfrozen soil and introduces a cable within said trench, a vibrating or reciprocating moving blade breaks frozen soil and sod and angulated projections lift soil from the trench. The description for Baker patent details lifting soil from the trench, soil lifting to excavate a trench, maximum upward elevation of trench, and excavation from a trench. Its object as stated is to provide an efficient soil raising device for cutting a forming a trench and to provide vibratory blade cutting means. The vibrating plow is very complex, has many moving parts, and is costly to purchase and maintain.
7) U.S. Pat. No. 3,405,528 to Hansen and Speer, which illustrates method to create an artificial water table. Hansen describes a wedge-shaped subterranean plow attached to a shank which is pulled through the soil at a pre-selected depth. Hansen does not describe the use to help pull his machine into the soil, does not describe using the plow to minimally disrupt soil, does not describe its use as a point, in conjunction with slicing or trenching, nor to be used to minimize horizontal soil compaction. He is using it to lift a large area of soil for the purpose of a creating a temporary cavity.
8) U.S. Pat. No. 3,182,459 to T. H. Grether, et al, to illustrate an apparatus for positioning fluid barriers in soil. The concept is similar to my proposal, but fails to anticipate or identify the problems of getting the machine into the soil, fails to identify the horizontal compaction caused by the device as it would travel through most soils, and fails to solve many problems associated with moving fabric through a series of rods and severe turns.
Important problems with Grether
As designed, penetrating most soils would be difficult, and displacing 50 mm of most types of soils (except sand) would create horizontal compaction and a substantial trench that would require back-filling and compaction, leaving little soil for friction to pull the fabric from the machine, and little soil to hold the base of the fabric in the trench before back-filling, as stated. PA1 The horizontal compaction would create very stable side walls of the trench 50 to 75 mm apart, eliminating most chances of the soil sealing against the fabric. PA1 The defined fabric handling mechanisms would be very sensitive to variations in the tension created by the soil pulling the fabric through the machine. It is well-documented that fabric flowing over a pivot mechanism must have even tension across the breadth of fabric--the slightest pressure off-center would pull the fabric into a bunch and clog the machine. The same concept applies to the right angle conversion mechanism, fabric would tend to bunch and clog instead of flowing through as planned. In construction areas, where terrain is always variable, and therefore tension on the fabric is also variable, it is doubtful whether fabric would ever flow through this mechanism. PA1 Heavy, stiff, and/or doubled over fabrics would also add significantly to these fabric flowing concerns. PA1 As designed, a significant amount of time would be required to thread fabric, folded or not, through and around the rollers and rods, in-between 2 narrow plates, with no external access.
9) U.S. Pat. No. 2,393,395 to Millard illustrates a plow share opening up a furrow, vertical fabric unrolling in the furrow, and disc blades pushing soil back onto the fabric. This would only work in friable soils and is quite different from the current discussion.
10) U.S. Pat. No. 2,314,045 to Johnson illustrates installing fabric with a ground slitting disc, but does not address the current proposal. There are many functional problems associated with the prior art. But primarily, the prior art does not suggest the combination of a horizontal chisel point and the slicing blade, whose combination minimizes horizontal compaction and pulls the device into the soil. Nor does the prior art address the fundamental problems of variable fabric tensions and dimensions at the pivot points, which is probably why none were commercial successes.
Failure of silt fence usually occurs on a slope where silt fence has been installed with no compaction or poorly compacted soil and the soil is underwashed in a heavy or fast rainfall situation. Silt fence failure is a problem for the environment and for public officials dictated by law or control erosion.
Engineering specifications call for contractors to install posts a certain depth and for the trench to be compacted. Proper compaction is usually not achieved, nor attempted.
The problems for construction companies installing silt fence are the high cost of trenching machine, the repair costs of a complex machine, and the number of labor hours, which delay productivity, such as trenching speed, man-handling an awkward 92 cm roll especially in the wind, back-filling the trench, and compacting the soil.
The silt fence machine greatly improves productivity of labor by mechanically installing hundreds of meters of silt fence per hour in a consistent, high-quality manner an in all types of soil and terrain, greatly improves maneuverability because of its compact design, greatly improves the quality of installation in the soil by creating an optimum environment for effective compaction, and the productivity ultimately reduces costs to the general public.
The silt fence machine is a combination known parts and ideas, whose operation as a unit creates a synergism which greatly increases installation production and quality of the final product over all previous common practices and all attempts at solving the problems, in a simple, yet dynamic manner.